Expiratory flow-volume loop profile and patient outcome in chronic obstructive pulmonary disease in acute respiratory failure: a prospective observational study in a single intensive care unit.

BACKGROUND: Expiratory flow-volume (EFV) loops are continuously displayed on the screen of intensive care unit (ICU) ventilators. OBJECTIVES: It was the aim of this study to investigate the relationships of EFV to chronic obstructive pulmonary disease (COPD) patient outcome. METHODS: This is a prospective study on COPD patients who received invasive mechanical ventilation for acute respiratory failure in the ICU. Within the 24-hour post-intubation period, the angle of the EFV slope during the last 50% of expiration was computed and patients were stratified into 4 quartiles. Resistance, compliance of the respiratory system and change in end-expiratory lung volume above relaxation volume were assessed. Patients were followed up to hospital discharge. The main outcome was hospital mortality. Secondary outcomes were ICU mortality, length of ICU stay, duration of invasive ventilation, number of intubations, oxygen and non-invasive ventilation. RESULTS: Thirty-eight patients were analysed. The first quartile comprised 9 patients (median angle 11°, interquartile range 8-12), the second 10 patients (median angle 26°, range 19-30), the third 10 patients (median angle 42°, range 39-46), and the fourth 9 patients (median angle 53°, range 49-64). Hospital and ICU mortality were not different between groups. Lengths of ICU and hospital stay and length of invasive ventilation were significantly different between groups, with the highest values observed in the first quartile. The rate of oxygen use and non-invasive ventilation in the ICU and at hospital discharge was significantly different between groups, with the highest rate observed in the first quartile. There was a significant negative correlation between angle and resistance, compliance of the respiratory system and change in end-expiratory lung volume above the relaxation volume. CONCLUSION: The slope of the angle during the last 50% of expired volume in the COPD patients was associated with worsened respiratory mechanics and higher morbidity.

Late-onset post-lesional paroxysmal hypothermia: a case series and literature review.

BACKGROUND: Paroxysmal hypothermia (PH) is a rare condition characterized by recurrent episodes of spontaneous hypothermia, bradycardia, disorders of consciousness and, in some cases, hyperhidrosis. When associated with a detectable hypothalamic lesion, PH episodes usually occur shortly after the brain insult. METHODS: We performed a retrospective study to identify patients who had demonstrated at least one episode of symptomatic spontaneous PH as defined by (i) tympanic temperature < 35 °C; (ii) drowsiness and/or confusion state and/or coma; (iii) duration of the episode ≥ 24 h; (iv) absence of other condition resulting in hypothermia RESULTS: Among 8824 patients, we identified four patients with recurrent late-onset PH episodes of 1-26-day duration that occurred 6-46 years after the brain insult. The lesion always involved the diencephalon. All patients suffered from epilepsy and three of hypopituitarism. PH episode typically included severe hypothermia, bradycardia, drowsiness, thrombocytopenia and in some patients central hypoventilation and narcolepsy-like hypersomnia. In » of episodes, confusion was mistaken as non-convulsive epileptic manifestation resulting in benzodiazepine administration which aggravated symptoms. In the two patients with nocturnal hypoventilation, chronic non-invasive ventilation with bi-level positive airway pressure allowed cessation of symptomatic episodes. DISCUSSION: Late-onset post-lesional PH is exceptional with only a single case hitherto reported in the literature. Distinguishing hypothermia-related disturbances of consciousness from epileptic seizures or post-ictal phenomena is crucial since treatment with benzodiazepines may worsen hypothermia through their action on GABAa receptors. Lastly, PH may be associated with sleep disorders and hypoventilation, for which investigations and treatment should be considered.